The prior art includes numerous prosthetic elbow joints to be worn by persons who were either born with no elbow, forearm and hand or whose arm had been amputated in the upper arm above the elbow. Most of the prior art prosthetic elbow joints generally include a turntable for affixing to the upper arm part of the prosthesis, a pivotal elbow joint, and a forearm. The most prominently used prosthetic elbow joint appears to be Models Numbered E-400 and E-400HD made and sold by Hosmer Dorrance Corporation, Campbell, Calif., as described in its catalogs, 10th edition (copyright 1983) and 11th edition (copyright 1986). These prior art prosthetic elbow joints have three major drawbacks or disadvantages. The first drawback or disadvantage of these prior art elbow joints reside in the fact that their extremely complex and fragile structure are not only costly to manufacture and sell, but the joints often fail when subjected to heavy use by many of its wearers. The second drawback or disadvantage relates to the extreme complexity of these devices and their numerous parts which make the elbow joints very difficult to disassemble, requiring the use of several different tools, a particularly difficult task for a person with only one hand. A third drawback or disadvantage of these prior art prosthetic elbow joints resides in their appearance in that the forearm part of the prosthesis is affixed to the elbow by an external steel fork which is exposed on the outside of the prosthesis. While a flesh colored plastic cap covers the mechanisms, the cap is hidden in part by the large steel fork which straddles the cap to give an overall, unnatural, appearance.
The present invention overcomes the several disadvantages, drawbacks or deficiencies of the prior art devices in that it provides a very strong joint which can withstand the repeated heavy loading encountered by a wearer who works in an industrial, construction, farming or similar environments. The strength of the present invention is due to the locking method utilized, a pin through a locking wheel loaded in double shear. The present invention is also very simple, having fewer parts, being less expensive to manufacture, and designed to be easily and quickly disassembled by a person with only one hand by use of only a screwdriver, penknife or other simple tool. The present invention also has the advantage of being fully covered by a single, flesh colored, rubber sleeve to give a more natural appearance.
Accordingly, it is an object of the present invention to provide a prosthetic elbow joint which is simple in construction, inexpensive to manufacture, and which incorporates locking features that can withstand repeated heavy loadings.
It is still a further object of the present invention to provide a prosthetic elbow joint which is simple in construction, inexpensive to manufacture, pleasing in appearance, and adapted to be easily locked and unlocked in several different positions.
Other aspects, objects and advantages of this invention will become apparent to those skilled in the art to which this invention pertains from a study of the preferred embodiment as set forth in the specification, drawings and appended claims.